Field of the Disclosure
The present disclosure relates to a method for processing subtitles in 3D video content. In particular, the present disclosure relates to a method for detecting subtitles in 3D video content, the result of which being used in interpolating intermediate images, for example in multi-view 3D TV environments. The present disclosure also relates to a device for detecting subtitle areas in 3D image content as well as a computer program and a non-transitory recording medium.
Description of Related Art
In the art, applications are known realizing a detection of subtitle areas in video images. The detection of subtitle areas is helpful when interpolating intermediate frames which are required for frame rate up-conversion. One application is, for example, disclosed in US 2010/0328529 A1. This document discloses an approach to detect a still subtitle part included as a part of an image in a video signal.
Although the known applications for subtitle detection in video images are satisfying in 2D video image environments, they do not work with the desired accuracy in 3D video image environments, e.g. 3D multi-view systems requiring a depth/disparity estimation for interpolating images. However, the estimation process is difficult with objects covering each other, like subtitles resulting in wrongly assigned depth information to certain areas of the image. In particular, it may happen that when interpolating 3D images in a multi-view system, the disparity of subtitles is corrupted by background motion. When viewing 3D video images, an inaccurate or temporal unstable disparity of subtitles will lead to very visible and annoying artefacts. In contrast to normal 2D video content, a viewer knows exactly how subtitles should look like on the screen, and the viewer also expects that the subtitles have temporally stable depth impression.
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventor(s), to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.